<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <ul id="ul">
      <li>1</li>
      <li>2</li>
      <li>3</li>
      <li>4</li>
    </ul>
    <script>
      const ul = document.getElementById("ul");
      const li = document.createElement("li");
      li.innerHTML = "new li";
      setTimeout(() => {
        // ul.insertAdjacentElement("beforeend", li); //append
        // ul.insertAdjacentElement("afterbegin", li); //perpend
        // ul.insertAdjacentElement("afterend", li); //after
        ul.insertAdjacentElement("beforebegin", li); //brefor
      }, 3000);
    </script>
  </body>
</html>
